Stamped envelopes, hearings, Apr. [4, 5] 1910 [on H. 2136, to amend act making appropriations for Post-Office Department, fiscal year 1908, so as to enable local printers to publish return requests, advertising, etc., on stamped envelopes, H. 21592, to authorize embossing of postage stamps on paper to be made into envelopes, and H. 23098, prohibiting printing of certain matter on stamped envelopes and sale thereof].